In an article published on September 18, 2024, in the Journal of Hazardous Materials, Weikun Meng from Nanjing University of Science and Technology, China, and co-authors introduced the development and use of a database comprising chemical features connected with plastic food packaging.
In their database, the researchers differentiate between, (1) chemical features suspected in plastics, and (2) non-target chemical features. To compile (1), Meng and co-authors searched Web of Science for scientific studies published between 2000 and 2020 using the terms “food packaging plastic” and “plastic”. From the 788 eligible studies as well as the Union List of the regulation on plastic materials and articles intended to come into contact with foodstuffs (EC 10/2011), they extracted chemical information such as CAS number, chemical formula, exact mass, and pseudomolecular ions.
To compile (2), the scientists used 106 plastic food packaging samples made of polypropylene (PP), polyethylene glycol terephthalate (PET), high-density polyethylene (HDPE), polycarbonate (PC), polystyrene (PS), low-density polyethylene (LDPE), tritan copolyester (Tritan), and unspecified plastics. They ground the samples, extracted the chemicals with dichloromethane/acetone using ultrasonication, applied the extracts to liquid chromatography high-resolution mass spectrometry (LC-Orbitrap-HRMS), and analyzed the mass spectra with TraceFinder.
As a result, Meng et al. established a database of 2101 distinct chemical features including 1176 suspects (step 1) and 925 non-target features (step 2).
In three experimental setups, they further explored which features migrate, and are present in foodstuffs and human samples. Using three food simulants, they undertook migration experiments with 106 packaging samples following the Chinese Food Safety Standard GB 5009.156–2016. In addition, they extracted the chemicals from 107 food samples and 108 human serum samples from Wuxi City, China.
The authors detected 625 of the 2101 chemical features in the migrates (189 suspects, 439 non-target) and 989 in the foodstuff samples (487 suspects, 502 non-target). Chemicals were present across all different types of food investigated, representing around 95% of the foods consumed by most people. Concerning presence in humans, 657 features were detected in at least one of the serum samples (344 suspects, 313 non-target).
As a reliability assessment of their database, the authors used authentic standards to confirm the identity of 33 features that were detected in at least 20% of serum samples and at least one food simulant. Here, 17 chemicals could be confirmed. Examples are 2,6-di-tert-butyl-p-benzoquinone (BHT-Q, CAS 128-37-0), phenyl sulfone (DPS, 1535-65-5), erucamide (EA, 112-84-5), tributyl acetylcitrate (ATBC, CAS 77-90-7), and di(2-ethylhexyl) phthalate (DEHP, CAS 117-81-7). All 17 chemicals were detected in the plastic food packaging, foodstuff, and human serum samples analyzed in the study.
Meng and co-authors also acknowledged that their study has several limitations such as not considering the Food Packaging Forum’s Food Contact Chemicals database (FCCdb) on chemicals intentionally used in food contact nor the Database on Migrating and Extractable Food Contact Chemicals (FCCmigex) on chemicals measured in migrates and extracts of food contact materials and articles. In addition, they did not include metabolites of plastic chemicals in their biomonitoring but acknowledged they might even have a higher detection frequency. A study by the Food Packaging Forum published in September 2024, systematically assessed the food contact chemicals found in the FCCdb and FCCmigex, and their metabolites, for presence in humans (FPF reported).
Meng and co-authors, further emphasized that they did not determine the identity of the plastic chemical features and that non-target chemical features were established by manual instead of automated screening. Still, they concluded, “that the number of plastic chemicals in our bodies could be far greater than previously recognized.”
Reference
Meng, W. et al. (2024). “Tracking chemical feature releases from plastic food packaging to humans.” Journal of Hazardous Materials. DOI: 10.1016/j.jhazmat.2024.135897
